Ammunition



Patented June 2, 1931 UNITED STATES.

PATENT OFFICE TAGE F. WERME, OF FAIRFIELD, CONNECTICUT, ASSIGNOR TO REMINGTON ARMS COM- PANY, INC., A. CORPORATION OF DELAWARE mmumrron No Drawing.

This invention relates to ammunition, particularly small arms ammunition, and has for its object the provision of ammunition such that erosion and corrosion of the bore of the gun barrel will be eliminated or reduced to a minimum. It is well known among the users' of firearms that ordinary ammunition is very destructive of the surface of the bore of the gun in which it is fired, corrosion and pitting of the bore taking place within a few hours unless the gun is carefully cleaned. Even thorough cleaning by the usual methods is ineffective to prevent corrosion. At the present time, corrosion is especially destructive of guns which shoot centerfire ammunition, a noncorrosive rim fire ammunition being now available. By the present invention, noncorrosive center fire as well as rim fire ammunition becomes possible.

It has long been thought and is now universally recognized as true, that corrosion is due to residues left in the bore by the com bustion of the propellent powder, and the priming'mixture used to ignite the powder. Potassium chlorate contained in either the powder or the priming mixture is the agent which is chiefly, if not entirely, responsible forcorrosion. On the firing of the charge, the potassium chlorate yields oxygen leaving a residue of highly hygroscopic potassium chloride, which is'driven by the high pressuresprevailing in thegun barrel into microscopic fissures and indentations in the bore, from which it cannot be removed by mechanical swabbing or by the use of the or dmary so-called gun cleaning compositions,

since it is insoluble in the fluids contained in such compositions. The present invention contemplates protecting the bore of the gun from corrosion by coating the bore with a substance which will fill and close any tool marks or indentations in the bore as well as coating the entire surface of the bore with a film which is .both impervious to' moisture and prevents the contact of destructive chloride or other residues with the'surface of the steel. Lead or its compounds are utilized for this purpose. A prior patent discloses the use of lead oxide for this purpose. The invention of saidpatent, however, contemplated the ad- Application filed November 19, 1927. Serial No. 234,553..

found to deteriorate with time and exposure to a moist atmosphere. The addition of stabilizing ingredients to prevent such deterioration presents substantial difliculties, since the volume of priming mixture which can be placed in small arms ammunition, especially small arms ammunition manufactured in accordance with the quantity production methods universally used in this country, is very limited. The present invention therefore contemplates the addition of lead dust or certain lead compounds to the propellent powder.

It has been discovered that when lead dust in quantities up to 12% by weight is added to the propellent powder a coating is formed on the. bore of the gun which substantially eliminates corrosion. It is thought that this coating may be, in part at least, an amalgam of mercury and lead, the, mercury being supplied by the decomposition of the mercury fulminate contained'in the priming mixture.

' The coating thus formed adheres well to the surface of'the steel, and forms an excellent protection against corrosion. Barrels in which my improved ammunition has been fired havewithstood very severe moisture tests with no sign of rust or pitting. Moreover, the coating material does not accumulatein the bore, or interfere with its accuracy after long continued firing. Any excess of the coating material appears to be removed by the passage of the bullet or blown out with the powder blast, and the accuracy is never impair'ed.

The lead dust may be incorporated with .the powder in the course of its manufacture Compounds of lead such for example as lead oxide, may he used in place of metallic lead with excellent results.

Applicant being the first to discover that corrosion may be reduced or eliminated h the admixture of lead or its compounds with the propellent powder of small arms ammunition, the construed.

What is claimed is:

1. The method of producing a cartridge capable of preventing corrosion in the bore of the gun in which the cartridge is to he fired, which comprises intermixing with the propellent charge a quantity oflead dust capable of forming a corrosion preventing coating in the bore of the gun when the cartridge is fired therein.

2. The method of preventing corrosion in the bore of a gun, comprising the incorporation in the propellent powder of a cartridge of a quantity of lead dust, and then forming a corrosion preventing coating containing such lead in the bore by firing the said cartridge in the gun.

3. A small-arms cartridge containing a propellent powder in which lead dust is intermixed in a quantity sufiicient to form a corrosion preventing coating in the bore of the gun in which the cartridge is fired.

4. A small-arms cartridge containing a propellent charge in which lead dust is intermixed in a quantity up to 12% by weight of the charge to form a corrosion preventive coatin in the bore of the gun in which the cart-ri ge is firedf appended claims are to be broadlyaeoasia TAGE F. wERim. 

